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ekino/neo4j-cluster

Description

Get a Neo4J cluster in no time.

Licensing

This repo uses Neo4J Enterprise, installed following the official and publicly available page http://debian.neo4j.org/.

You must have a license to use Neo4J Enterprise, and as a consequence to use this repo.

For more informations :

• Licenses : http://neo4j.com/subscriptions/
• Contact : http://neo4j.com/contact-us/

TL;DR

If you are on linux :

# start a neo4j cluster w/ 3 nodes
curl -sSL https://raw.githubusercontent.com/ekino/docker-neo4j-cluster/master/helper.sh | bash -s run:neomaster,neoreadslave,neobackup

Cluster Creation

Prerequisites

Clone the repo :

git clone git@github.com:ekino/docker-neo4j-cluster.git neo4j-cluster
cd neo4j-cluster

Cluster initialisation (manual)

# Build dns server image (so nodes can communicate to each others)
docker build -t=ekino/dnsmasq:latest dns/

# Build neo4j-cluster node image
docker build -t=ekino/neo4j-cluster:latest node/

# Start dns server
docker run --name neodns -h neodns -v $(readlink -f dns/dnsmasq.d):/etc/dnsmasq.d -d ekino/dnsmasq:latest
localdns=$(docker inspect --format {{.NetworkSettings.IPAddress}} neodns)

# Start neo4j-cluster nodes
docker run --name neo1 -h neo1 --dns $localdns -e SERVER_ID=1 -e CLUSTER_NODES=neo1,neo2,neo3 -P -d ekino/neo4j-cluster:latest
docker run --name neo2 -h neo2 --dns $localdns -e SERVER_ID=2 -e CLUSTER_NODES=neo1,neo2,neo3 -P -d ekino/neo4j-cluster:latest
docker run --name neo3 -h neo3 --dns $localdns -e SERVER_ID=3 -e CLUSTER_NODES=neo1,neo2,neo3 -P -d ekino/neo4j-cluster:latest

# Register nodes to dns server
echo "host-record=neo1,$(docker inspect --format {{.NetworkSettings.IPAddress}} neo1)" | tee dns/dnsmasq.d/50_docker_neo1
echo "host-record=neo2,$(docker inspect --format {{.NetworkSettings.IPAddress}} neo2)" | tee dns/dnsmasq.d/50_docker_neo2
echo "host-record=neo3,$(docker inspect --format {{.NetworkSettings.IPAddress}} neo3)" | tee dns/dnsmasq.d/50_docker_neo3
docker exec neodns supervisorctl restart dnsmasq

# Check your host ports forwared to 7474 for each nodes
docker ps

# For each forwared port go to
http://localhost:<FORWARDED_PORT>/webadmin/#/info/org.neo4j/High%20Availability/

Cluster initialisation (auto)

WARNING: Before you proceed, be aware the 'clear' argument kills and rm all docker containers !

For convenience, you can use the helper.sh file to remove old or running container, build new images, start the new containers and/or check the cluster configuration.

Arguments :

• clear: kill running containers + remove all containers
• clear:all: same as clear + remove untagged/dangled images
• build: build ekino/dnsmasq and ekino/neo4j-cluster images
• run:NODES: run all listed NODES (comma separated)

Arguments can be added to the commandline. They will be processed in order.

# oneline command equivalent to manual install above : (/!\ it remove all your containers /!\)
./helper.sh clear:all build run:neo1,neo2,neo3

Cluster Usage

Either use neo4j-shell command, http dashboard or rest api...

The End ?

For this POC, we have used dnsmasq so the nodes can talk to each other. but we could have used more complex but powerful tools like etcd, consul, ....

Next, we'll talk about data persistence and neo4j extensions.